第19月第17天 uitextview 文本垂直居中 uiimage中间不拉伸

1.

open class VericalCenteringScrollView: UIScrollView {
    override open var contentOffset: CGPoint {
        didSet {
            let contentSize = self.contentSize
            let scrollViewSize = self.bounds.size

            var contentOffset = self.contentOffset

            if contentSize.height < scrollViewSize.height
            {
                contentOffset.y = -(scrollViewSize.height - contentSize.height) / 2.0;
            }

            super.contentOffset = contentOffset
        }
    }
}

2.

+ (UIImage *)createLoadingImage:(UIColor *)color size:(CGSize)size centerImage:(UIImage *)image2
{
    /*生成loadingImage,中心为image2*/
    UIGraphicsBeginImageContext(size);

    // Draw image1
//    [image1 drawInRect:CGRectMake(0, 0, size.width, size.height)];
    CGRect rect=CGRectMake(0.0f, 0.0f, size.width, size.height);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetFillColorWithColor(context, [color CGColor]);
    CGContextFillRect(context, rect);

    // Draw image2
    [image2 drawInRect:CGRectMake((size.width-image2.size.width)/, (size.height-image2.size.height)/, image2.size.width, image2.size.height)];

    UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return resultingImage;
}